This invention relates generally to the art of pipe networks for buildings and especially to apparatus and systems for making fire-retardant pipe networks.
Until recently, pipe networks were normally extended through floors of buildings by forming holes in the walls--e.g. by using void-forming devices during the "pouring" of the floors, by knocking out holes, by boring such holes after the floors had been formed, etc.--and thereafter extending pipes through these holes. Normally the holes were made to be bigger than the pipes to ensure that one could easily extend the pipes through the holes. Thereafter, it was necessary for workmen to fill the spaces between the pipes and the holes with cement or some other substance in order to meet fire codes which generally do not allow holes in floors.
There have been a number of patent documents published such as German Offenlegungsschrift No. 2,615,428, Harbeke (4,453,354) and Cornwall (4,261,598) disclosing the concept of cementing pipe-coupling joints into floors when the floors are poured and thereafter, mating external pipes to female opposite ends of the embedded coupling joints. Such a practice is normally carried out with plastic pipe, however, it could also be carried out with pipes made of other materials.
A major fire problem which still exists for plastic pipe-coupling joints which are embedded in floors is that when there is a fire the fire will melt the external plastic pipes and then pass up through the pipe-coupling joints themselves to the next higher floors. In other words, the pipe coupling joints themselves serve as ventilation holes for fires. It is an object of this invention to provide an assembly and structure for extending a pipe network through a building floor using embedded plastic pipe coupling joints without allowing the pipe joints themselves to become fire ventilation holes.
It is a further object of this invention to provide a method and assembly for embedding a pipe coupling joint in a concrete floor in such a manner that in the event of a fire the coupling joint is closed off to the flow of air, heat and fire through the coupling joint.
It is a further object of this invention to provide a fire-retardant fluid coupling which acts quickly enough to prevent a fire from spreading to the next higher story through a bore of the fluid coupling.
It has been suggested to use mechanical valves for closing off embedded pipe coupling joints in case of fire, however the operation of such mechanical valves deteriates over time so that when fires occur many years after a building has been built the valves may not properly function. It is an object of this invention to provide an embedded fire-retardant pipe coupling joint which does not involve mechanically moving parts.
It is still another object of this invention to provide such a fire-retardant fluid coupling which can be easily mounted on a concrete form for embedding the coupling in concrete.